From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: [PATCH v2 1/3] KVM: x86: clear bus pointer when destroyed Date: Tue, 21 Mar 2017 10:24:15 +0100 Message-ID: <420f6aef-9461-e582-f080-409b4a074335@redhat.com> References: <1489564879-6097-1-git-send-email-peterx@redhat.com> <1489564879-6097-2-git-send-email-peterx@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Paolo Bonzini , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= To: Peter Xu , kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:58788 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756477AbdCUJZn (ORCPT ); Tue, 21 Mar 2017 05:25:43 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2BBDD64DA0 for ; Tue, 21 Mar 2017 09:24:20 +0000 (UTC) In-Reply-To: <1489564879-6097-2-git-send-email-peterx@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 15.03.2017 09:01, Peter Xu wrote: > When releasing the bus, let's clear the bus pointers to mark it out. If > any further device unregister happens on this bus, we know that we're > done if we found the bus being released already. > > Signed-off-by: Peter Xu > --- > virt/kvm/kvm_main.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index a17d787..7445566 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -727,8 +727,10 @@ static void kvm_destroy_vm(struct kvm *kvm) > list_del(&kvm->vm_list); > spin_unlock(&kvm_lock); > kvm_free_irq_routing(kvm); > - for (i = 0; i < KVM_NR_BUSES; i++) > + for (i = 0; i < KVM_NR_BUSES; i++) { > kvm_io_bus_destroy(kvm->buses[i]); > + kvm->buses[i] = NULL; > + } > kvm_coalesced_mmio_free(kvm); > #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) > mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); > @@ -3579,6 +3581,14 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, > struct kvm_io_bus *new_bus, *bus; > > bus = kvm->buses[bus_idx]; > + > + /* > + * It's possible the bus being released before hand. If so, > + * we're done here. > + */ /* the bus might have already been destroyed */ ? Reviewed-by: David Hildenbrand > + if (!bus) > + return 0; > + > r = -ENOENT; > for (i = 0; i < bus->dev_count; i++) > if (bus->range[i].dev == dev) { > -- Thanks, David